A series of some 3-13 monohydroxy eicosanoic acid isomers were evaluated for their antielastase, antiurease and antioxidant activities for the first time in this study. All the test compounds exhibited antielastase, antiurease and antioxidant activities. According to the obtained results the hydroxy eicosanoic acid isomers locating in the middle and close to the middle of the chain showed higher antielastase, antiurease and antioxidant activities rather than that of the other isomers. Therefore, 3-13 monohydroxy eicosanoic acid isomers can be used in agriculture, pharmacy and cosmetic industries due to their excellent antielastase, antiurease and antioxidant activities

3-, 7-and 13-Monoketo tetradecanoic acid methyl esters carrying a keto group at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein-Ponndorf-Verley reaction in the presence of R-(+)-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(-)-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1 H-NMR shift with Eu(tfc) 3 and by optical rotation.